1. Field of the Invention
The present invention relates to a method of forming metal wiring and metal wiring formed using the same, and more particularly, to a method of forming metal wiring and metal wiring formed using the same, which can improve electrical and mechanical properties.
2. Description of the Related Art
As electronic devices and information terminal devices have become smaller and lightweight, electronic components mounted in such devices have also been reduced in size. This requires wiring patterns for mounting inside electronic components to have smaller sizes and widths and smaller spacing between the wiring patterns.
An optical patterning method based on exposure and etching is in common use to form high-resolution patterns for electronic devices. However, this optical patterning method is wasteful of materials and requires complicated multistage processes due to the use of photoresist, developer or etching solution for example, thus imparing process efficiency. Moreover, a large mask needs to be used in the optical patterning process, and this makes it difficult to quickly apply a new design to a production line. In order to overcome those limitations of the optical patterning, an inkjet printing method has been developed that allows the formation of patterns directly on a substrate without using a mask while minimizing the number of processes and the material consumption.
The inkjet printing method may substitute for the optical patterning method, and is an eco-friendly technique, unlike the existing optical patterning. The inkjet printing method is currently under development in various corporations, schools and institutes. The inkjet printing method is expected to significantly contribute to saving production costs in the fields of electronic/electric components and displays.
The inkjet printing method is widely applicable because it allows any material, which can be made into ink, to be printed selectively and rapidly as fine patterns. In the process of inkjet printing, ink is sprayed onto a target position in a non-contact manner. For this reason, shapes can be freely printed on a substrate such as paper, fabrics, metal, ceramics or polymer. Also, inkjet printing allows for large-area printing for large posters or banners of a few square meters, for example.
Wiring formed by the inkjet printing method is dependent upon the amount of wiring material being printed, in terms of the widths of wiring patterns or spacing therebetween. Thus, the selection of the wiring material is an important issue. Of late, an inkjet printing method using metallic nanoparticles has been introduced, in which the metallic nanoparticles have a stable fine structure through a thermal process. Research is ongoing to achieve the optimized fine structure of metallic nanoparticles because the fine structure thereof affects the electrical and mechanical characteristics of metal wiring.